[Steve L]

My bike is in pieces right now. I have done air box modifications, the air box snorkel is removed but no hole is cut in the top. I have placed six air box vents on the left side. I plan on putting a FMF titanium powercore and FMF powerbomb header. I have a JD Jet kit and I have also put an R&D Powerbowl on the carburetor and I have done the pink wire mod.
I need to know if my air box will have adequate breathing without cutting the top and should I follow the JD jetting kit recommendations, which would be red needle clip on the fifth position, main jet 158, pilot jet 42, and the air screw 1 and 3/4 turns out, also, I have replaced the detent spring as per the R&D Powerlbowl instructions.
Any help would be greatly appreciated as I would love to ride soon.
Thx! Steve

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Welcome to the site Steve !
I'd sure start anyway with the JD kit recommendations and ride it with those and see how it goes.
As far as the airbox goes I'm not sure. Honda did mold in the cut lines so they did have an idea how they thought it should be done. You can always try it with your holes,and if you run it slow,medium and high speeds and the plug is black and sooty then that would mean you need more air.
If you decrease the jetting sizes or lean the needle to bring the plug to the right (tan) color instead of opening the airbox further, then you're cheating yourself out of some power.
You could e-mail JD and tell him just what you have , I think he sells the R&D Powerbowl so he may be of some guidance there in regards to how that may or may not affect the baseline jetting recommendations,same with the airbox mod. I can pretty much promise you he'll say the whole thing should come off according to the cut guides.
Remember that with FCR carbs even jetted perfectly that if sitting still in neutral from an idle you CAN make the bike bog if you whack the throttle hard enough, so don't go chasing your tail on that.
Also Steve, your bike will now gain rpm very quickly, if you think you are experiencing a bog but it's only at high rpms you're not, it's the rev limiter.
Sounds like a nice set-up, let us know how it works ! Doug

[Steve L]

I jetted the carburetor per the JD Jetting Kit instructions and cut the top of the air box out and installed all the other things I mentioned in my first post. The bike started after about 4-5 kicks with no chokes and idled perfect with NO bog. It has quick throttle response and it's like having a new bike. I can pull wheelies in the first three gears and bounced off the rev limiter. I love it.

I like the website and I was reading the message boards before I made any modifications. All the information I obtained from this website was right on the money.

[Asmith]

I jetted the carburetor per the JD Jetting Kit instructions and cut the top of the air box out and installed all the other things I mentioned in my first post. The bike started after about 4-5 kicks with no chokes and idled perfect with NO bog. It has quick throttle response and it's like having a new bike. I can pull wheelies in the first three gears and bounced off the rev limiter. I love it.

I like the website and I was reading the message boards before I made any modifications. All the information I obtained from this website was right on the money.

Glad to hear everything worked like it should.

Our 250X is jetted the same as yours.

Like the new power??? Just wait until you put in an "R" cam!!! It's like getting a new bike all over again...

Keep your eyes peeled... we got a brand new one off EBay for $ 40.00.

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Outstanding Steve, pretty sweet,huh ? Doug